The extension of hyper-Rayleigh scattering, from a technique for the experimental determination of the first hyperporarizability, beta, of molecules in solution, to a means of determining the molecular structure of monomers and polymers in solution, is discussed in this paper. The theoretical framework for this extension is given and the instrumental set-up is described. It is shown, with selected examples, that the information from hyper-Rayleigh scattering alone is sufficient to deduce a consistent structural picture of advanced molecules and polymers in solution. (C) 2000 Elsevier Science B.V. All rights reserved.